The goals are to 1) implemetn automatic tuning and impedance matching on whole body, surface coil, catheter/needle, and implantable resonators; 2) increase the Q of the transmission line used in surface coil resonators; 3) decrease the size and increase the operational depth of catheter/needle style resonators; and 4) develop a new configuation involving two resonators and two detectors, with rapid shifting, to allow measurements at two different sites in the same experimental period.